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1.
Med Oral Patol Oral Cir Bucal ; 25(2): e283-e290, 2020 Mar 01.
Article in English | MEDLINE | ID: mdl-31967981

ABSTRACT

BACKGROUND: The purpose of this experimental study was to compare the immunohistochemical expression of SOX2 and BCL-2 in Odontogenic Keratocyst (OKC) and Ameloblastoma (AB) specimens, and to identify a possible correlation in their expression. MATERIAL AND METHODS: Immunohistochemical analysis was performed to evaluate SOX2 and BCL-2 expression in OKC (n = 20) and AB (n = 20). The immunoexpression was analyzed by a quantitative and qualitative scoring system. The comparison between the immunoexpression of SOX 2 and BCL-2 was assessed by the Mann-Whitney U-test. Spearman's correlation coefficient evaluated the correlation between SOX2 and BCL-2 expressions. RESULTS: SOX2 and BCL-2 expression was observed in all specimens of OKC in the full thickness of the epithelium lining. SOX2 immunostaining was higher in OKC, in comparison with AB samples (P<0.05). BCL-2 immunostaining between OKC and AB was not statistically significant. There was no significant correlation between SOX2 and BCL-2 in OKC and AB specimens. CONCLUSIONS: SOX2 and BCL-2 expressions in OKC may suggest their relationship with the biological behavior of this lesion, and the higher expression of SOX2 might be an upstream influence on the Hh signaling pathway.


Subject(s)
Ameloblastoma , Odontogenic Cysts , Odontogenic Tumors , Humans , Proto-Oncogene Proteins c-bcl-2 , SOXB1 Transcription Factors
2.
J Comp Pathol ; 171: 6-11, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31540627

ABSTRACT

Canine visceral leishmaniosis (CVL) is an important zoonotic disease, which is endemic in Brazil and several other parts of the world. The disease may affect multiple organs, but lesions in the oral cavity are considered uncommon. Twenty-three cases of oral lesions compatible with CVL were diagnosed from 2015 to 2018 in the Federal District, Brazil. Six cases were confirmed to be CVL based on histopathology, immunohistochemistry and polymerase chain reaction amplification of Leishmania infantum kDNA. Most of the affected dogs were >9 years of age, of mixed breed and were classified as having stage C of the disease. The most important gross findings were ulcerated nodular lesions in the tongue, lip, gingiva and hard palate. Microscopically, there was lymphoplasmacytic to granulomatous inflammation that was diffuse, moderate to severe and associated with ulceration. CVL should be considered in the differential diagnosis of nodular and ulcerative oral lesions in dogs.


Subject(s)
Dog Diseases/pathology , Leishmaniasis, Visceral/veterinary , Mouth/pathology , Animals , Dogs , Leishmania infantum , Leishmaniasis, Visceral/pathology , Retrospective Studies
3.
Int Endod J ; 51(1): 79-85, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28439909

ABSTRACT

AIM: To evaluate the alterations promoted by a thermally deposited siloxane-methacrylate coating on the surface of glass fibre posts and their effect on the bond strength of resin-core materials to the posts. METHODOLOGY: Fibre post surfaces were treated with experimental thermally deposited siloxane-methacrylate coatings or clinically available treatments (i.e. hydrogen peroxide and methylene chloride); nontreated posts were used as controls. The contact angles formed between the post surface and the water/adhesive were measured with a tensiometer. Scanning electron microscopy and electron dispersive spectroscopy were used to examine the topographies and chemical changes in the post surfaces following treatment. Surface roughness was evaluated with laser interferometry. Core resin was bonded to the fibre posts, and microtensile bond strength testing was subsequently performed. The data were individually submitted to anova and Tukey's tests (α = 0.05). RESULTS: The water contact angle was reduced significantly (P < 0.05) by the thermally deposited siloxane-methacrylate coating. All treatments significantly increased the adhesive contact angle (P ≤ 0.016) compared to the control as well as the surface roughness (P ≤ 0.006) and the amount of Si on post surfaces. Greater percentages of Si were observed for the thermally deposited coating. The bond strength to the posts was significantly improved by the thermally deposited coating (P < 0.05), whereas the other treatments did not differ from the control. CONCLUSION: Treating the surface of glass fibre posts with a thermally deposited siloxane-methacrylate coating improved the bond strength to resin-based materials. The coating could be performed by manufacturers of glass fibre posts in order to reduce the number of clinical steps required for luting posts into root canals.


Subject(s)
Dental Bonding , Glass , Methacrylates , Post and Core Technique , Siloxanes , Tensile Strength , Humans , Materials Testing
4.
Genet Mol Res ; 12(3): 2594-600, 2013 Jan 04.
Article in English | MEDLINE | ID: mdl-23315874

ABSTRACT

Breast cancer is the second most common origin of brain metastases, after lung cancer, and represents 14-20% of all cases. Abnormalities of chromosome 17 are important molecular genetic events in human breast cancer, and several oncogenes and tumor suppressor genes are located on this chromosome. In about half of all human cancers, the tumor suppressor gene TP53, located at 17p13.1, is either lost or mutated. Loss of p53 protein function influences not only cell cycle checkpoint controls and apoptosis, but also the regulation of other important stages of metastatic progression, such as cell migration and tissue invasion. The aim of our study was to identify numerical aberrations of chromosome 17 and TP53 in 5 subjects with brain metastasis from breast cancer using dual-color fluorescence in situ hybridization experiments. Deletion of TP53 was the most frequent alteration observed, suggesting that if this alteration is present in the primary tumors, breast tumors with loss of TP53 copies have a poorer prognosis and a higher chance for metastasis. If this is true, the analyses of chromosome 17 and TP53 in primary breast cancer could be important for predicting its metastatic potential.


Subject(s)
Adenocarcinoma/pathology , Brain Neoplasms/genetics , Breast Neoplasms/pathology , Chromosome Aberrations , Chromosomes, Human, Pair 17/genetics , Tumor Suppressor Protein p53/genetics , Adult , Brain Neoplasms/secondary , Female , Gene Deletion , Humans , Middle Aged
5.
Toxicon ; 52(8): 944-53, 2008 Dec 15.
Article in English | MEDLINE | ID: mdl-18948130

ABSTRACT

BJ-32 (also known as BjcuL) is a C-type lectin from the venom of Bothrops jararacussu with specificity for beta-galactosides and a remarkable ability to agglutinate several species of trypanosomatids. Our objective was to study the oligomerization state of native BJ-32 by using different biophysical and computational methods. Small-angle X-ray light scattering (SAXS) experiments disclosed a compact, globular protein with a radius of gyration of 36.72+/-0.04A and molecular weight calculated as 147.5+/-2.0kDa. From analytical ultracentrifugation analysis, it was determined that the BJ-32 sedimentation profile fits nicely to a decamer model. The analysis of the intrinsic emitted fluorescence spectra for BJ-32 solutions indicated that association of subunits in the decamer is accompanied by changes in the environment of Tryptophan residues. Both ab initio and comparative models of BJ-32 supported the resemblance of the decamer in the crystallographic structure from a close homologue, the rattlesnake venom lectin (RSL) from Crotalus atrox.


Subject(s)
Bothrops , Crotalid Venoms/chemistry , Lectins, C-Type/chemistry , Amino Acid Sequence , Animals , Circular Dichroism , Computer Simulation , Crotalid Venoms/analysis , Crotalid Venoms/isolation & purification , Lectins, C-Type/analysis , Lectins, C-Type/isolation & purification , Models, Molecular , Molecular Sequence Data , Protein Structure, Quaternary , Scattering, Small Angle , Sequence Alignment , Spectrometry, Mass, Electrospray Ionization , Ultracentrifugation
6.
Braz. j. phys. ther. (Impr.) ; 10(3): 263-269, jul.-set. 2006. graf
Article in Portuguese | LILACS | ID: lil-445436

ABSTRACT

CONTEXTUALIZAÇÃO: Estudos têm identificado que as propriedades dos objetos induzem os ajustes no alcance; no entanto, poucos investigaram a influência específica do tamanho e rigidez dos objetos em lactentes jovens. OBJETIVO: Verificar se lactentes de 4 a 6 meses realizam ajustes proximais e distais ao alcançarem objetos de diferentes tamanhos e rigidez. MÉTODOS: Nove lactentes saudáveis foram posicionados em uma cadeira inclinada a 50º. Quatro objetos foram apresentados, um rígido grande (RG), um rígido pequeno (RP), um maleável grande (MG) e um maleável pequeno (MP), por um período de 1 minuto cada. Em um total de 384 alcances, foram analisados os ajustes proximais (alcance uni e bimanual) e distais (orientação da mão horizontal, vertical e oblíqua; mão aberta, fechada e semi-aberta) e o sucesso do alcance dos objetos. RESULTADOS: Constatou-se ajuste bimanual para o objeto RG e unimanual para os demais. A orientação da mão oblíqua foi predominante no toque dos objetos, enquanto para a preensão dos mesmos, a predominância foi a vertical, principalmente para o objeto RG. A orientação horizontal não foi observada na preensão do objeto RG. A mão semi-aberta foi mais freqüente no início do alcance para todos os objetos, enquanto no toque do objeto RG a mão aberta foi predominante. O sucesso do alcance foi maior para os objetos maleáveis (MG, MP) do que para os rígidos (RG e RP). CONCLUSÃO: Lactentes jovens estudados são capazes de planejar e ajustar seus movimentos baseados na percepção das propriedades físicas dos objetos, o que sugere interação percepção-ação.


BACKGROUND: Studies have identified that object properties lead to adjustments to reaching. However, few have investigated the specific influence of object size and rigidity among young infants. OBJECTIVE: To verify whether four to six-month-old infants make proximal and distal adjustments when reaching for objects of different sizes and rigidity. METHOD: Nine healthy infants were seated on a chair inclined at 50º. Four objects were presented to them: one large rigid (LR), one small rigid (SR), one large malleable (LM) and one small malleable object (SM), each for a one-minute period. A total of 384 reaches were analyzed to verify proximal adjustments (single-hand and two-hand reaching) and distal adjustments (horizontal, vertical and oblique hand orientation; opened, closed and half-open hand), and the success in reaching the objects. RESULTS: The infants exhibited two-hand adjustments for the LR object and single-hand adjustments for the other objects. Oblique orientation was predominant for touching the objects, while vertical orientation was predominant for grasping them, particularly the LR object. Horizontal orientation was not observed for grasping the LR object. At the start of reaching for all objects, the hands were most frequently half-open, while the hands were predominantly open when touching the LR object. Success was greater when reaching for malleable objects (LM, SM) than for rigid objects (LR and SR). CONCLUSION: The young infants studied were capable of planning and adjusting their movements on the basis of their perceptions of the physical properties of the objects, which suggests that perception-action interaction was occurring.


Subject(s)
Infant , Aptitude , Motion Perception , Physical Phenomena , Psychomotor Performance , Upper Extremity
7.
Article in English | MEDLINE | ID: mdl-16750943

ABSTRACT

Affinity chromatography based on the commercial resin Sepharose CL-6B was used to isolate new C1-beta-type lectins from crude preparations of snake venoms (Bothrops jararaca, Bothrops jararacussu, Bothrops newiedi, Bothrops moojeni, Lachesis muta rhombeata). Most of the C-type lectins could be eluted with almost 100% recovery using the competitor isopropyl-beta-D-thiogalactoside (IPTG) or through Ca2+ sequestration with EDTA. The lectin yield varied considerably among the different snake species, but B. newiedi venom was a particularly rich source of lectin, retaining 2.7 mg of lectin by milliliter of resin in saturating conditions. C1-alpha-lectins from Crotalus durisus terrificus venom, from the jack fruit (jacalin) and from bread fruit seeds extract (frutalin) had no affinity, either with or without Ca2+ added, for Sepharose CL-6B, showing that the resin is specific for C1-beta-type lectins. Sepharose CL-6B used as galactose-affinity chromatography provides a simple and fast method for isolating C-type beta-galactoside binding lectins from crude sample preparations.


Subject(s)
Chromatography, Affinity/methods , Galectins/analysis , Amino Acid Sequence , Animals , Bothrops/metabolism , Crotalid Venoms/analysis , Crotalid Venoms/chemistry , Crotalid Venoms/pharmacology , Galectins/chemistry , Galectins/isolation & purification , Hemagglutination Tests , Humans , Sepharose/analogs & derivatives , Sepharose/chemistry , Sequence Analysis, Protein , Sequence Homology, Amino Acid , Species Specificity , Viper Venoms/analysis , Viper Venoms/chemistry , Viper Venoms/pharmacology , Viperidae/metabolism
8.
Article in English | MEDLINE | ID: mdl-15994137

ABSTRACT

Snake venoms contain several trypsin-like enzymes with equivalent physicochemical characteristics and similar inhibition profiles. These are rather difficult to separate by classical purification procedures and therefore constitute a good model for affinity chromatography analysis. Some of these trypsin homologues present fibrinogenase activity, mimicking one or more features of the central mammalian coagulation enzyme, thrombin. It was previously demonstrated that a number of amidine derivatives are able to interact specifically with some of these serine proteases. To understand the enzyme-sorbent interactions we have investigated the ability of two commercially available benzamidine affinity matrices to purify thrombin-like serine proteases (TLSP) with similar biological properties from two snake venoms (Bothrops jararacussu and Lachesis muta rhombeata). Curiously, each sorbent retained a single but distinct TLSP from each venom with high yield. Molecular modeling analysis suggested that hydrophobic interactions within a specific region on the surface of these enzymes could be generated to explain this exquisite specificity. In addition, it was demonstrated that a specific tandem alignment of the two benzamidine sorbents enables the purification of three other enzymes from B. jararacussu venom.


Subject(s)
Benzoylarginine Nitroanilide/chemistry , Chromatography, Affinity/methods , Crotalid Venoms/enzymology , Sepharose/analogs & derivatives , Serine Endopeptidases/isolation & purification , Viper Venoms/enzymology , Amino Acid Sequence , Animals , Bothrops , Hydrophobic and Hydrophilic Interactions , Models, Molecular , Sepharose/chemistry , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/chemistry , Viperidae
9.
Phytomedicine ; 9(7): 641-5, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12487329

ABSTRACT

Incubation of acyclovir-resistant herpes simplex virus type 1 (ACVr-HSV1), during infection of the HEp-2 cell culture, with an extract prepared from the seeds of Licania tomentosa (Benth.) Fritsch (Chrysobalanaceae) species impaired the productive replication of this virus in a concentration-dependent manner. The extract was able to inhibit extracellular virus (virucidal effect) and also interfered with a very early event of cell infection, at a non-cytotoxic concentration.


Subject(s)
Antiviral Agents/pharmacology , Herpesvirus 1, Human/drug effects , Plant Extracts/pharmacology , Rosales , Brazil , Humans , Seeds/chemistry , Temperature , Time Factors , Tumor Cells, Cultured
10.
FEBS Lett ; 514(2-3): 141-8, 2002 Mar 13.
Article in English | MEDLINE | ID: mdl-11943140

ABSTRACT

Blood flukes of the genus Schistosoma currently infect millions of people in tropical and subtropical countries. An enzyme playing a major role in hemoglobin (Hb) degradation by Schistosoma mansoni has been cloned and shown to be highly similar to the human cathepsin D aspartyl proteinase, although presenting a distinct substrate specificity from the latter. Investigating the structural features responsible for this difference has a major application in the design of selective anti-schistosomal drugs. In order to achieve this goal a homology model for the S. mansoni aspartyl hemoglobinase was constructed and then used to simulate the complexes formed with two transition state analogues of Hb-derived octapeptide substrates. Comparison with human cathepsin D showed that different pocket volumes and surface electrostatic potentials arise from substitutions in residues comprising the S4, S3, S2 and S3' subsites. Since the primary specificity of the S. mansoni enzyme resembles that of HIV-1 protease, we have discussed the applicability of current retroviral protease inhibitors as leads for the design of new anti-schistosomal drugs.


Subject(s)
Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/physiology , Helminth Proteins , Models, Molecular , Schistosoma mansoni/enzymology , Animals , Binding Sites , Cathepsin D/chemistry , Cathepsin D/physiology , HIV Protease/chemistry , Hemoglobins/chemistry , Humans , Macromolecular Substances , Mice , Molecular Sequence Data , Peptide Fragments/chemistry , Phylogeny , Sequence Alignment , Sequence Homology, Amino Acid , Structure-Activity Relationship , Substrate Specificity/physiology
11.
Rev Hosp Clin Fac Med Sao Paulo ; 56(4): 123-30, 2001.
Article in English | MEDLINE | ID: mdl-11717720

ABSTRACT

We report on 4 cases of abdominal compartment syndrome complicated by acute renal failure that were promptly reversed by different abdominal decompression methods. Case 1: A 57-year-old obese woman in the post-operative period after giant incisional hernia correction with an intra-abdominal pressure of 24 mm Hg. She was sedated and curarized, and the intra-abdominal pressure fell to 15 mm Hg. Case 2: A 73-year-old woman with acute inflammatory abdomen was undergoing exploratory laparotomy when a hypertensive pneumoperitoneum was noticed. During the surgery, enhancement of urinary output was observed. Case 3: An 18-year-old man who underwent hepatectomy and developed coagulopathy and hepatic bleeding that required abdominal packing, developed oliguria with a transvesical intra-abdominal pressure of 22 mm Hg. During reoperation, the compresses were removed with a prompt improvement in urinary flow. Case 4: A 46-year-old man with hepatic cirrhosis was admitted after incisional hernia repair with intra-abdominal pressure of 16 mm Hg. After paracentesis, the intra-abdominal pressure fell to 11 mm Hg.


Subject(s)
Abdomen/physiopathology , Acute Kidney Injury/etiology , Compartment Syndromes/complications , Abdomen/surgery , Adolescent , Aged , Compartment Syndromes/surgery , Decompression, Surgical , Female , Humans , Male , Middle Aged
12.
J Appl Physiol (1985) ; 89(2): 437-44, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10926624

ABSTRACT

We studied the respiratory and blood pressure responses to chemical stimulation of two regions of the ventral brainstem in mice: the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively). Stimulation of the RVLM by microinjections of the excitatory amino acid L-glutamate induced increases in diaphragm activity and breathing frequency, elevation of blood pressure (BP), and a slight increase in heart rate (HR). However, activation of the CVLM induced a decrease in breathing frequency, mainly due to prolongation of expiratory time (TE), and hypotension associated with a slight slowing of HR. Because adrenergic mechanisms are known to participate in the control of respiratory timing, we examined the role of alpha(2)-adrenergic receptors in the RVLM region in mediating these inhibitory effects. The findings demonstrated that blockade of the alpha(2)-adrenergic receptors within the RVLM by prior microinjection of SKF-86466 (an alpha(2)-adrenergic receptor blocker) significantly reduced changes in TE induced by CVLM stimulation but had little effect on BP responses. These results indicate that, in mice, activation of the RVLM increases respiratory drive associated with an elevation of BP, but stimulation of CVLM induces prolongation of TE via an alpha(2)-adrenergic signal transduction pathway.


Subject(s)
Cardiovascular Physiological Phenomena , Medulla Oblongata/physiology , Respiratory Physiological Phenomena , Adrenergic alpha-2 Receptor Antagonists , Adrenergic alpha-Antagonists/pharmacology , Animals , Benzazepines/pharmacology , Catecholamines/metabolism , Catecholamines/physiology , Diaphragm/physiology , Electric Stimulation , Glutamic Acid/pharmacology , Hemodynamics/drug effects , Hemodynamics/physiology , Hypertension/physiopathology , Medulla Oblongata/anatomy & histology , Medulla Oblongata/cytology , Mice , Mice, Inbred C57BL , Neurons/metabolism , Neurons/physiology , Receptors, Adrenergic, alpha-2/physiology , Respiratory Mechanics/drug effects , Respiratory Mechanics/physiology , Stereotaxic Techniques , Tyrosine 3-Monooxygenase/biosynthesis
13.
Brain Res ; 862(1-2): 26-35, 2000 Apr 17.
Article in English | MEDLINE | ID: mdl-10799665

ABSTRACT

In the mouse medulla oblongata, we characterized binding properties and functional responses of two recognition sites for imidazoline compounds: I(1)-imidazoline and alpha(2)-adrenergic receptors. The mouse medulla expresses a higher density of I(1)-receptors than in the rat, whereas alpha(2)-receptor densities were similar between the two species. In anesthetized, ventilated and paralyzed mice, we tested the hypotensive actions of the I(1)/alpha(2) agonist moxonidine, determined its central site of its actions, and the relative roles of I(1) and alpha(2)-receptors. Experiments were performed in C(57)Bl(6) wild type and alpha(2A)-adrenergic receptor deficient mice. In both types of mice, neuronal activation within the rostral ventrolateral medulla (RVLM) region by glutamate microinjection elicited increases in arterial pressure. Moxonidine (0.5 nmol/site/10 nl) microinjected bilaterally into this vasopressor region decreased arterial pressure by 30% and heart rate by 11% in wild type mice. Efaroxan, the I(1)/alpha(2) antagonist (0.4 nmol) when microinjected into the RVLM elevated blood pressure itself and abolished the action of moxonidine, whereas alpha(2)-blockade with SK&F 86466 had no significant effect on blood pressure and did not attenuate moxonidine's effect. To more definitively test the role of alpha(2)-adrenergic receptors in the action of moxonidine, moxonidine was microinjected into the RVLM of alpha(2A)-adrenergic deficient mice. The decreases in arterial pressure were nearly identical to those of wild type mice, whereas bradycardia was attenuated. Thus, in the mouse moxonidine acts within the RVLM region to lower arterial pressure mainly through the I(1)-imidazoline receptor independent of alpha(2)-adrenergic receptors.


Subject(s)
Antihypertensive Agents/pharmacology , Imidazoles/pharmacology , Receptors, Adrenergic, alpha-2/genetics , Receptors, Adrenergic, alpha-2/metabolism , Adrenergic alpha-2 Receptor Antagonists , Adrenergic alpha-Antagonists/pharmacology , Amygdala/chemistry , Amygdala/metabolism , Animals , Benzofurans/pharmacology , Binding, Competitive , Blood Pressure/drug effects , Brain Chemistry/drug effects , Glutamic Acid/pharmacology , Heart Rate/drug effects , Hypertension/drug therapy , Imidazoline Receptors , Injections, Intravenous , Medulla Oblongata/chemistry , Medulla Oblongata/metabolism , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Microinjections , Pons/chemistry , Pons/metabolism , Receptors, Drug/analysis , Receptors, Drug/antagonists & inhibitors , Receptors, Drug/metabolism
14.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;31(10): 1339-43, Oct. 1998. ilus, tab, graf
Article in English | LILACS | ID: lil-223997

ABSTRACT

Several studies demonstrate that, within the ventral medullary surface (VMS), excitatory amino acids are necessary components of the neural circuits involved in the tonic and reflex control of respiration and circulation. In the present study we investigated the cardiorespiratory effects of unilateral microinjections of the broad spectrum glutamate antagonist kynurenic acid (2 nmol/200 nl) along the VMS of urethane-anesthetized rats. Within the VMS only one region was responsive to this drug. This area includes most of the intermediate respiratory area, partially overlapping the rostral ventrolateral medulla (IA/RVL). When microinjected into the IA/RVL, kynurenic acid produced a respiratory depression, without changes in mean arterial pressure or heart rate. The respiratory depression observed was characterized by a decrease in ventilation, tidal volume and mean inspiratory flow and an increase in respiratory frequency. Therefore, the observed respiratory depression was entirely due to a reduction in the inspiratory drive. Microinjections of vehicle (200 nl of saline) into this area produced no significant changes in breathing pattern, blood pressure or heart rate. Respiratory depression in response to the blockade of glutamatergic receptors inside the rostral VMS suggests that neurons at this site have an endogenous glutamatergic input controlling the respiratory cycle duration and the inspiratory drive transmission.


Subject(s)
Animals , Male , Rats , Excitatory Amino Acid Antagonists/adverse effects , Kynurenic Acid/adverse effects , Medulla Oblongata , Respiration/drug effects , Blood Pressure/drug effects , Heart Rate/drug effects , Microinjections , Rats, Wistar
15.
Braz J Med Biol Res ; 31(10): 1339-43, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9876307

ABSTRACT

Several studies demonstrate that, within the ventral medullary surface (VMS), excitatory amino acids are necessary components of the neural circuits involved in the tonic and reflex control of respiration and circulation. In the present study we investigated the cardiorespiratory effects of unilateral microinjections of the broad spectrum glutamate antagonist kynurenic acid (2 nmol/200 nl) along the VMS of urethane-anesthetized rats. Within the VMS only one region was responsive to this drug. This area includes most of the intermediate respiratory area, partially overlapping the rostral ventrolateral medulla (IA/RVL). When microinjected into the IA/RVL, kynurenic acid produced a respiratory depression, without changes in mean arterial pressure or heart rate. The respiratory depression observed was characterized by a decrease in ventilation, tidal volume and mean inspiratory flow and an increase in respiratory frequency. Therefore, the observed respiratory depression was entirely due to a reduction in the inspiratory drive. Microinjections of vehicle (200 nl of saline) into this area produced no significant changes in breathing pattern, blood pressure or heart rate. Respiratory depression in response to the blockade of glutamatergic receptors inside the rostral VMS suggests that neurons at this site have an endogenous glutamatergic input controlling the respiratory cycle duration and the inspiratory drive transmission.


Subject(s)
Excitatory Amino Acid Antagonists/adverse effects , Kynurenic Acid/adverse effects , Medulla Oblongata , Respiration/drug effects , Animals , Blood Pressure/drug effects , Heart Rate/drug effects , Male , Microinjections , Rats , Rats, Wistar
16.
Respir Physiol ; 108(1): 23-33, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9178374

ABSTRACT

We investigated the cardiorespiratory effects elicited by microinjections of L-glutamate (L-glu, 25 nmol, 200 nl) at various sites in the ventral medulla (VMS) of urethane-anesthetized rats. The results demonstrated that regions responsive to the drug are located along a column in the VMS extending from the VI cranial nerve to the first cervical nerve in the caudal medulla. Within this column three breathing patterns were elicited from four distinct areas. In the most rostral and caudal portion of this hypothetical column, the breathing patterns observed in response to L-glu were similar and characterized by increases in minute ventilation, tidal volume, inspiratory drive, respiratory frequency, mean arterial blood pressure (MAP) and heart rate (HR). In the regions located between the areas described above two different breathing patterns were obtained without significant changes in MAP or HR. These patterns were characterized by decreases and increases in the respiratory indices analyzed, with the exception of respiratory frequency, which decreased in both regions. These results suggest that within the VMS discrete areas may act as functional units modulating cardiorespiratory responses while in others these functions are spatially segregated.


Subject(s)
Cardiovascular System/drug effects , Glutamic Acid/pharmacology , Medulla Oblongata/drug effects , Respiration/drug effects , Animals , Cardiovascular Physiological Phenomena , Male , Medulla Oblongata/anatomy & histology , Medulla Oblongata/physiology , Microinjections , Rats , Rats, Wistar , Respiration/physiology , Respiratory Physiological Phenomena , Respiratory System/drug effects
17.
Braz J Med Biol Res ; 26(8): 879-96, 1993 Aug.
Article in English | MEDLINE | ID: mdl-7905329

ABSTRACT

1. To study the action of the intermediate area (IA), coextensive with the rostral ventrolateral medulla, on the neurophysiological mechanisms involved in the regulation of respiration, in terms of inspiratory drive and respiratory timing, cats were submitted to topical application of sodium pentobarbital (30 mg/ml), leptazol (200 mg/ml), glutamate (50 mg/ml) and glycine (100 and 50 mg/ml) to the IA. The effects of electrically induced exercise on the ventilatory response and oxygen uptake (VO2) obtained by topical application of glycine (50 mg/ml) to the IA were also studied. 2. Leptazol reduced minute ventilation (VE) and inspiratory drive (VT/TI) and changed the timing mechanism. Glutamate only increased tidal volume (VT), VE and VT/TI. Arterial blood pressure (AP) increased and heart rate (HR) did not change with either drug. 3. Sodium pentobarbital reduced VT and changed the timing mechanism. Glycine only reduced VE, VT and VT/TI. AP decreased and HR did not change with either drug. 4. The depressor effects of glycine on respiratory pattern, VO2 and CO2 production (VCO2) tended to be attenuated by exercise. 5. The fall in AP due to glycine application did not differ between resting and exercise conditions. 6. Our results indicate that at least two different nervous structures are involved in the IA: one responsible for the respiratory drive and sensitive to glycine and glutamate, and the other responsible for the regulation of the timing mechanism and sensitive to sodium pentobarbital and leptazol.


Subject(s)
Glycine/pharmacology , Medulla Oblongata/drug effects , Respiration/drug effects , Animals , Blood Pressure/drug effects , Cats , Electric Stimulation , Female , Glutamates/pharmacology , Glutamic Acid , Heart Rate/drug effects , Male , Medulla Oblongata/physiology , Oxygen Consumption/drug effects , Pentobarbital/pharmacology , Pentylenetetrazole/pharmacology , Respiration/physiology , Rest/physiology , Time Factors
18.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;26(8): 879-96, Ago. 1993. tab, graf
Article in English | LILACS | ID: lil-148761

ABSTRACT

1. To study the action of the intermediate area (IA), coextensive with the rostral ventrolateral medulla, on the neurophysiological mechanisms involved in the regulation of respiration, in terms of inspiratory drive and respiratory timing, cats were submitted to topical application of sodium pentobarbital (30 mg/ml), leptazol (200 mg/ml), glutamate (50 mg/ml) and glycine (100 and 50 mg/ml) to the IA. The effects of electrically induced exercise on the ventilatory response and oxygen uptake (VO2) obtained by topical application of glycine (50 mg/ml) to the IA were also studied. 2. Leptazol reduced minute ventilation (VE) and inspiratory drive (VT/TI) and changed the timing mechanism. Glutamate only increased tidal volume (VT), VE and VT/TI. Arterial blood pressure (AP) increased and heart rate (HR) did not change with either drug. 3. Sodium pentobarbital reduced VT and changed the timing mechanism. Glycine only reduced VE, VT and VT/TI. AP decreased and HR did not change with either drug. 4. The depressor effects of glycine on respiratory pattern, VO2 and CO2 production (VCO2) tended to be attenuated by exercise. 5. The fall in AP due to glycine application did not differ between resting and exercise conditions. 6. Our results indicate that at least two different nervous structures are involved in the IA: one responsible for the respiratory drive and sensitive to glycine and glutamate, and the other responsible for the regulation of the timing mechanism and sensitive to sodium pentobarbital and leptazol


Subject(s)
Animals , Male , Female , Cats , Glycine/pharmacology , Medulla Oblongata/drug effects , Respiration , Oxygen Consumption , Heart Rate , Glutamates/pharmacology , Medulla Oblongata/physiology , Pentobarbital/pharmacology , Pentylenetetrazole/pharmacology , Arterial Pressure , Respiration/physiology , Rest/physiology , Time Factors
19.
J. pneumol ; 10(1): 28-31, 1984.
Article in Portuguese | LILACS | ID: lil-23012

ABSTRACT

Sao apresentados 24 casos de silicose em cavadores de pocos cuja idade media era de 44 anos (29 a 58). Todos eram sintomaticos sendo os sintomas mais comuns a dispneia e a tosse. Todos apresentaram lesoes radiologicas, predominando a fibrose pulmonar nos lobos superiores. O eletrocardiograma mostrou sobrecarga de camara direita em tres casos, bloqueio de ramo direito em dois, sendo normal em 19 casos.A espirometria revelou um disturbio funcional misto em 12 casos, restricao pura em cinco, obstrucao pura em tres e foi normal em quatro casos


Subject(s)
Adult , Middle Aged , Humans , Male , Silicosis
20.
Revista da Associacao Paulista de Cirurgioes Dentistas;66(4): 298-302,
in Portuguese | URUGUAIODONTO | ID: odn-23935
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